Hi Richard,
Skyline is for targeted mass spec, which is to say it's assumed that you already have an idea of what's in your sample. It's not a search tool per se.
That said, you can certainly populate a transition list from a spectral library, perform chromatogram extraction, and see what matches well with your sample and what doesn't. It's not a sophisticated way to approach search but might be a useful first order filter.
Thanks for using the Skyline support board!
Brian Pratt